{"schema":"threatline.record/2","record":{"id":"CVE-2026-97935","aliases":[],"summary":"tracing: Set the trace clock before registering the histogram trigger","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Set the trace clock before registering the histogram trigger\n\nhist_register_trigger() puts the trigger on the global named_triggers\nlist in cmd_ops->init(), and only then sets the trace clock:\n\n\tif (data->cmd_ops->init) {\n\t\tret = data->cmd_ops->init(data);\n\t\tif (ret < 0)\n\t\t\tgoto out;\n\t}\n\n\tif (hist_data->enable_timestamps) {\n\t\tret = tracing_set_clock(file->tr, hist_data->attrs->clock);\n\t\tif (ret) {\n\t\t\thist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));\n\t\t\tgoto out;\n\t\t}\n\nThe clock string is not checked anywhere before that call, so a named\ntrigger using common_timestamp with an unknown clock fails after it has\nalready become findable. event_hist_trigger_parse() then frees it\nwithout taking it off the list, and the next lookup by name reads the\nfreed object:\n\n ~# cd /sys/kernel/tracing/events/sched/sched_switch\n ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger\n bash: echo: write error: Invalid argument\n ~# echo 'hist:name=foo:keys=common_pid' > trigger\n\n  BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0\n  Read of size 8 at addr ffff88800915d760 by task init/1\n   find_named_trigger+0xac/0xc0\n   hist_register_trigger+0xc1/0x900\n   event_hist_trigger_parse+0x3146/0x6af0\n   event_trigger_write+0xce/0x160\n  Freed by task 63:\n   kfree+0x154/0x420\n   trigger_kthread_fn+0xfd/0x160\n\nSet the clock before the trigger is registered, so that nothing which\ncan fail runs after it is published, the way commit 6f86bdeab633\n(\"tracing: Fix bad hist from corrupting named_triggers list\") moved the\nregistration below the rest of the setup.\n\ntracing_set_filter_buffering() is reference counted, so the init failure\npath has to drop the reference that the clock block now takes first.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","source_modified_at":"2026-10-21T12:53:44.309Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"a4072fe85ba3671720cab0788291af953db27318","lessThan":"578d39ab420b18b76a12fc8d0573ec041a84da28","status":"affected","versionType":"git"},{"version":"a4072fe85ba3671720cab0788291af953db27318","lessThan":"cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad","status":"affected","versionType":"git"},{"version":"a4072fe85ba3671720cab0788291af953db27318","lessThan":"cfad128171f8e2237a3c723d6478ef2cfb3b9127","status":"affected","versionType":"git"},{"version":"a4072fe85ba3671720cab0788291af953db27318","lessThan":"65d1e28198f344832a8a63e8ccf84b8f65b92a32","status":"affected","versionType":"git"},{"version":"a4072fe85ba3671720cab0788291af953db27318","lessThan":"6ede78d0563a2a3ae3e46f9c07cedb5d79645429","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","source_modified_at":"2026-10-21T12:53:44.309Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.17","status":"affected"},{"version":"0","lessThan":"4.17","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","source_modified_at":"2026-10-21T12:53:44.309Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"578d39ab420b18b76a12fc8d0573ec041a84da28","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","source_modified_at":"2026-10-21T12:53:44.309Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"65d1e28198f344832a8a63e8ccf84b8f65b92a32","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","source_modified_at":"2026-10-21T12:53:44.309Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"6ede78d0563a2a3ae3e46f9c07cedb5d79645429","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.05745,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:22:49.820Z","modified_at":"2026-10-21T12:53:44.309Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:53:44.309Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-97935","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/578d39ab420b18b76a12fc8d0573ec041a84da28"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:53:44.309Z","content_hash":"142d9dd36bca6afbd09c5ab7376b198e1aa9ef23d38bb3ad6d11e4413ce60330"}}